An excellent rifle for hunting or plinking, the Hatsan BT65 SB will deliver significant knockdown power no matter which caliber you choose. However, if you generally hunt for medium-size game such as beavers, woodchucks, muskrats, or nutria, the .22 or .25 caliber would be your best choice.

Things I liked:Wow...that is all that needs to be said. This gun is a powerhouse! The build is excellent and the gun shoots like a gem. I am extremely happy with the purchase.Things I would have changed:I would scrap the Bipod and include the adapter to fill the gun using a foster quick fill station.What others should know:Let me say something about Pyramydair.com. They don't make companies like this anymore. The customer service is top-notch. They truely care about the customer and will do whatever it takes to make you happy. Thank you, PyramydAir!!!

I like you, am new to PCP guns. When I bought my first one a few months back I was forgetting to open The quick bleed off valve and I tore up an O-Ring in 3 fills. Then I replaced both O-Rings and I add a drop of Crosman lube in the tube on each seal before filling my gun. I have an AT44Wood-10 .22 and a new Galation Black .25. I have tried both fill probes and they work the same. Great now! But like I said, a drop of Crosman silicon oil on each seal and I try to point the little hole in the probe between the rings towards the butt and I hold the probe with a slight bit of pressure and do the slow fill. Then quick release and slip the probe out. I have 2 tanks 80cf and I have not had one nicked O-Ring in 5 tanks full of air. Try that and I think you will find it works slick.

Sounds like there is a nick in an o-ring. If replacing them with the ones provided with the gun does not help (and an application of silicone oil or silicone grease) the size of the o-rings are #009. Maybe the surfaces of the probe or the probe port are damaged. www.hatsanusa.com

I feel compelled to amend my previous post. I am having a real problem with the fill probe leaking a ton of air. I have to open the valve on my air tank all the way in order to get a charge of up to 170 bar. They recommend charging it slowly however I cannot do that because all it does is leak if I open the valve slowly. What can I do to fix this? For the price of this rifle I can't believe the fill probe is giving me so much trouble. Very disappointed with this issue.

Things I liked:The power of this rifle, in .25 cal, is phenomenal. The rifle is very comfortable, for me at 6'6" and 250. May be a bit on the heavy side for some. Things I would have changed:The rifle could stand a beter final machining/Q/A process. True to what others have posted the bolt is EXTREMELY hard to operate untill the gun gets a thorough cleaning/deburring and a few rounds shot through it. What others should know:Make sure you perform a thorough cleaning/inspection before you try and sight the rifle in. Seems to be very accurate with the JSB exacts. Tested with numerous other pellet styles/weights but they seem to be all over the target at 25 yards. Make sure you check the bolt chamber as mine had several burrs that were causing the bolt to bind and make the gun difficult to operate as well as putting a few minor scratches on the bolt.

Things I liked:+This gun hits hard, works excellent on small game. +Price is fair.
+I like how the gun loads magazines from right to left allowing you to easily place and use a large parallax adjuster on Hawke Sidewinder scopes.
+adjustable cheekpiece/comb and buttstock.
+easy to mount scopes and bipods on this gun.
+rugged magazines.
+Iron sights(tru-glo fiber optic sights)included.
+Sling swivel studs included
+2 mags included
+threaded barrelThings I would have changed:-I think that this gun would be better with a different type of fill adapter (like a foster or the type that Air Arms use.), the probe adapter is kind of a pain to use and if you dont shut off the valve on your fill tank fast enough (and I mean fast) the on-board air reservoir begins to lose air out of the probe. Making it hard to fill it all the way up to 200 bar.
-Little better trigger would be nice, it is a two stage trigger but it is a a little rough. it's not terrible but it's not great either. I also own a AAS510 Carbine in .22 cal and the trigger is much nicer but the gun was also twice as much.
-The cocking bolt is extremely stiff, it does loosen up with use but it still takes a lot of force to cock even after a couple hundred rounds. I think a sidelever cocking arm would have made the action much easier because you could have gotten some leverage.
-better bedding of the rifle in the stock or a firmer stock. the stock twists and flexs even with a little force.
-The automatic safety. (every time you cock the bolt the safety automatically gets put on making follow up shot take that much longer.)
-better barrel bands.
-better bipods included with gun.
-on-board pressure gauge, would be better anywhere other than where it is. I get why it is where it is (for filling) but if you want to check the pressure you have to be on the business end of the gun.
-offer a model with a regulator.What others should know:*I can squeeze two full mags out the the reservoir, but I have a much better spread with the first 9-10 shots after that the FPS really starts dropping.
*This gun has more of a power slope not a power curve, hence why the shot count isnt as high as some other similar guns.
*using 25.4 gr JSB's the highest recorded FPS I got was 977.7 FPS.
*bipods that are included with the gun are terrible, consider replacing them when you buy the gun.
*the guns accuracy is pretty good, its not quite as good as my AA, which is why I took off 1 star for accuracy, but it is still good. For example my AAS510 will keyhole shots at 25m where as the BT65 will have the shots touching. However I have still made a 110+ yard head shot on a ground squirrel. With a regulator I would expect the groupings to get better.